Searchers for the flight recorders from the chartered Egyptian jetliner that crashed Saturday off the Egyptian coast say they need specialized equipment to retrieve the recorders. It will take several days for the equipment to arrive.

Search and recovery efforts in the Red Sea intensified in the effort to pinpoint the location of the flight data recorder and cockpit voice recorder from the ill-fated Boeing 737 that crashed shortly after takeoff Saturday.

The so-called black boxes contain the voice recordings of conversations between the pilots and technical data about the flight. The information in those boxes should help investigators determine why the plane plummeted into the sea killing all 148 people on board.

Lead investigators say a signal from one of the boxes indicates it may be in water so deep, special equipment will have to be brought to Egypt in order to retrieve it.

According to Egyptian and French authorities, radar data suggest the plane experienced a mechanical problem as it was taking off from the Egyptian resort Sharm el-Sheikh, bound for Paris.

Egyptian aviation officials say the plane climbed to 1,500 meters, made an unplanned turn to the right and crashed into the sea 17 seconds later at a speed of about 316 kilometers per hour.

Memorial services for the victims of the crash will be held Thursday in Sharm el-Sheikh. The majority of the passengers aboard the plane were French tourists. Many of their families have arrived in the resort to take part in ceremonies both on land and at sea. French Foreign Minister Dominique de Villepin will represent the French government at the ceremonies.